WE’RE ALL familiar with the standard threepart ‘clutch kit’ comprising a release bearing, a friction disc and a pressure plate. But there’s another equally vital component in the clutch mechanism that’s often overlooked.
The spigot (or ‘pilot’) bush or bearing lives in the end of the engine’s crankshaft.
It supports the end of the gearbox input shaft and allows the engine to spin while the gearbox remains stationary.
This wears over time and it’s worth replacing whenever you change the clutch. It may also start to bind or seize due to wear or the drying out of its lubricant.
This means you’ll have to force the car into first gear and engaging reverse will sound like an exercise in medieval torture.
In extreme cases, the car will creep forward in first gear with the clutch fully depressed.
If you’re suffering these problems, begin by making absolutely sure the clutch is disengaging fully. Try altering the adjustment, which may be at the pedal or gearbox end. If it’s a hydraulic system, make sure the reservoir is full and that the pedal doesn’t feel soft or spongy – the seals may be worn out. Lastly, don’t overlook a thick floor mat or new soundproofing that’s restricting pedal travel.
Spigot bushes and bearings are likely to be standard engineering sizes but the former could be manufacturer-specific. Always buy a rubbersealed bearing (denoted 2RS), which is lubricated and sealed for life. Go for a quality item – the hassle of premature replacement isn’t worth the saving of a few pounds.
You’ll have to remove the clutch to access the spigot bush or bearing. Check the rest of the components closely and replace any that aren’t perfect. If a friction disc for your classic is cheaply and readily available, it makes sense to replace this as a matter of course. (From Practical Classics, UK.)
Socket set, breaker bar, torque wrench, old fan belt, large hammer, clutch alignment tool and bearing puller (or DIY equivalents).
Soak the bush in oil for 24 hours – many have a sintered construction (eg, ‘Oilite’) that absorbs lubricant. Lightly grease it after installing.
A few cars have a short gearbox input shaft and no spigot bearing. Check your manual before trying to order one…
Make sure the new bush/ bearing fits the gearbox input shaft before fitting it.
If you can’t find a correct bush, an engineering shop will be able to make or adjust one.
REMOVE CLUTCH ‘Crack’ the pair of bolts at the bottom of the flywheel, then turn the engine to get to the next pair. Loosen all the bolts in stages. Be ready to catch the friction disc as you pull off the pressure plate.
BEWARE OF DUST Clutch dust may contain asbestos. Clean with a workshop-only vacuum cleaner and warm soapy water or brake cleaner.
Replace the friction disc if it’s worn.
Inspect the pressure plate for wear, too.
Dispose of cleaning rags in a sealed plastic bag when dry.
REFIT CLUTCH The friction disc needs to be perfectly centred before you tighten down the pressure plate. Use a clutch alignment tool, an old gearbox input shaft or sockets and extensions wrapped in tape.
IS IT NECESSARY? The flywheel will have to come off if it retains the bearing or bush. Otherwise, it can stay in place.
The bolts may be held by locking tabs, Loctite or simply by being very, very tight. Use a breaker bar.
FIND TDC You’ll need to lock the engine to undo the flywheel bolts. Turn engine to TDC of cylinder one (the rotor arm points to the number one segment in the cap). This ensures both valves are safely closed.
The adjuster raises or lowers the drop shaft to alter the mesh of the roller & worm.
LOCK THE ENGINE Turn the engine backwards past TDC and feed a length of a cut fan belt into the spark plug hole. Turn the engine toward TDC until it stops. Now the bolts can be undone without the crank turning.
‘Look for leaks from the gearbox input shaft and rear crankshaft oil seals. Now is a good time to replace them.’
FLYWHEEL ORIENTATION The flywheel may have uneven bolt spacing or dowel pegs to ensure it’s replaced as it came off. If not, mark its position relative to the crankshaft.
Putting it back differently may cause balance issues.
RETIGHTEN BOLTS To lock the engine to tighten the bolts, remove the fan belt from the cylinder.
Turn the engine forwards past TDC, then reinsert the fan belt and turn the engine backwards until it locks again.
TORQUE CORRECTLY Use a torque wrench to tighten the flywheel bolts according to your manual. They’ll be very tight (eg, 65lb ft). The clutch pressure plate bolts, meanwhile, are very modestly torqued (eg, 20lb ft).
INSERT CLAW of a slide hammer puller set (from $50) – usually the best tool for the job. Insert its clawed end through the centre of the bush/bearing, then tighten it to grip the inner face.
Use the slide hammer to shock out the bush or bearing.
Bearings are often held in by a circlip. Don’t forget to remove this first.
DIY BEARING PULLER Alternatively, find a large socket that fits over the bearing.
Find a long bolt, nut and washer.
The head of the bolt will hook under the bearing. The washer stops the nut pulling through the socket.
USING DIY PULLER Cut a slot in the end of the bolt. Put the socket in place and engage the bolt with the bearing.
Tighten the nut while holding the bolt still with a screwdriver. The bearing will slowly be drawn out.
Wind tape around the bar or mandrel if it’s slightly too small.
HYDRAULIC BUSH REMOVAL Fill the bush and the hole behind with grease.
Hammer in a close-fitting mandrel (an old gearbox input shaft, clutch aligning tool, length of round bar, etc.). Hydraulic pressure will force the bush out.
REPLACE BUSH/BEARING Check the new bush or bearing fits snugly on the gearbox input shaft. Drift it carefully in using a socket that bears on its outer shoulder. Don’t strike the inner track or the rubber seal of a bearing.